What type of plastid is responsible for the synthesis and storage of starch?

Plastids are a type of organelle found in plant cells. They have their own genetic material and can produce and store specific molecules, such as pigments, starch, and lipids.  Amyloplasts are non-pigmented plastids responsible for the synthesis and storage of starch, which is a carbohydrate that plants use as an energy source. 

Chloroplasts are responsible for photosynthesis and the production of oxygen and glucose. Leucoplasts are responsible for the synthesis of lipids, amino acids, and other molecules. Chromoplasts are responsible for the synthesis and storage of pigments, such as carotenoids and anthocyanins.

Hence, the correct answer is amyloplasts.