Vitamins B1, B2, and B3 all play roles in the metabolism of carbohydrates.

Vitamin K is essential for the synthesis of proteins required for blood clotting.

Vitamin B9, also known as folic acid, is known to prevent neural tube defects during pregnancy.

Vitamin B12 is primarily absorbed in the ileum of the small intestine.

Vitamin B12 is primarily absorbed in the ileum of the small intestine.

Vitamin B12 is primarily absorbed in the small intestine, specifically in the ileum.

Vitamin B12 is primarily found in animal products and is crucial for nerve function and the production of DNA and red blood cells.

Vitamin B12 is primarily found in animal products and is essential for the formation of red blood cells and DNA synthesis.

Vitamin B12 is primarily found in animal products and is crucial for nerve function and the production of DNA and red blood cells.

Vitamin D plays a crucial role in calcium absorption in the gut and maintaining adequate serum calcium and phosphate levels.

Vitamin A is essential for the formation of rhodopsin, a pigment in the retina that is crucial for vision.

Vitamin C is abundant in citrus fruits like oranges, lemons, and grapefruits.

Vitamin D is synthesized in the skin upon exposure to sunlight.

Vitamin D is produced in the skin when it is exposed to sunlight.

Vitamin D is synthesized in the skin when it is exposed to ultraviolet (UV) rays from sunlight.

Green light is least effective for photosynthesis because it is mostly reflected by chlorophyll.

Blue light is most effective for photosynthesis as it is absorbed strongly by chlorophyll.

The Pradhan Mantri Awas Yojana, launched in 2015, aims to provide affordable housing to the urban poor.

The Skill India Mission, launched in 2015, aims to provide skill training to the youth to enhance their employability.

The author expresses an urgent sentiment towards environmental conservation, stressing its importance.

The author expresses a hopeful sentiment towards conservation efforts, suggesting optimism for the future.

The author expresses frustration with current environmental policies, indicating a critical tone.

'Therefore' indicates a cause-and-effect relationship.

'Therefore' indicates that his preparation was a result of his studying.

The author shows an understanding attitude, recognizing the concerns of skeptics while advocating for action.

The author views education as critical for raising awareness and fostering informed action on climate change.

'Ubiquitous' means present everywhere or widespread, so 'common' is the best replacement in this context.

'Common' is the best replacement for 'ubiquitous', as it conveys the idea of smartphones being widely present in society.

'Arduous' means difficult, making option 2 the closest in meaning.

The word 'meticulous' means showing great attention to detail, which is closest in meaning to 'thorough'.