Answer the following question given this paragraph: 

Molecular formulas tell us how many atoms of each element are present in one molecule of a molecular compound. In many cases, the molecular formula is the same as the empirical formula. For example, the molecular formula of methane is CH 4 , and because 1:4 is the smallest whole-number ratio that can be written for this compound, that is also its empirical formula. Sometimes, however, the molecular formula is a simple whole-number multiple of the empirical formula. Acetic acid is an organic acid that gives vinegar its distinctive taste and smell. Its molecular formula is C 2 H 4 O 2 . Glucose is a simple sugar that cells use as their primary source of energy. Its molecular formula is C 6 H 12 O 6 . The structures of both molecules are shown in Figure below . They are very different compounds, yet both have the same empirical formula, CH 2 O.


Q: What simple sugar is the cell's primary source of energy?

 Choices:

- carbon

- nicotine

- chloride

- glucose

A:
glucose
