(d) For growing a crop, sufficient sunlight and water and nutrients from the soil are essential.
Crop or plants needs sufficient sunlight because sunlight is the main source of energy in plants by which it performs photosynthesis. During the process of photosynthesis plants absorb light energy from sunlight and uses it to produce glucose(from glucose plants obtain their energy to perform various functions) and oxygen(as waste material it is excreted out) by converting carbondioxide and water in presence of chlorophyll.
Water is also an essential part that contributes in plant's growth by transporting nutrients and minerals from soil to each and every part of the plant. It also helps during photosynthesis process.
Nutrients are obtained by the plants through their roots from the soil. It helps the plant to withstand various diseases that occur due to deficiency of some nutrients and also to fight viral and bacterial diseases. Nutrients also helps the plant to yield flavorful and colorful fruits and flowers.