There are three correct answers to this question. The first is A, Water. Along with the Sun, water is what helps plants grow. Water allows nutrients to be transported throughout the plant. Water also is what helps plants stand strong. The second correct answer is Insects and birds to pollenate flowers.
Insects can move the pollen to the parts of the plant that need it. Birds also transfer pollen to the flowers. The third correct answer to this question is D, Carbon dioxide (from animals and humans). Carbon dioxide is important during photosynthesis. It helps the plants grow at an increased rate.