Producers use energy from the sun to create or usable chemical energy.
a) fat
b) glucose
c) protein
d) starch

Producers are organisms that photosynthesize. The process of photosynthesis uses (the sun's) light, along with carbon dioxide and water to create a monosaccharide known as glucose. So, the answer is A: Glucose

D)can be increased in a closed system

There is one s orbital, and there are three p orbitals, five d orbitals, and seven f orbitals. thus, the answer is b. do not confuse the number of orbitals in a subshell with the number of electrons the subshell can hold. each orbital can hold two electrons, so the capacity of an nf subshell is 14 electrons.