Erythrocytes do not contain a nucleus. This would make answer choice "A" correct. Erythrocytes are red blood cells and these cells differ from the other cells of the body because of the absence of the nucleus. All the other cells noted have nuclei.
To find the number of CO₂ molecules, you need to start with 100 grams of butane (C₄H₁₀), convert to moles (using the molar mass), convert to moles of CO₂ (using coefficients from equation), then convert to molecules (using Avagadro's number). The molar mass of C₄H₁₀ is calculated using the quantity of each element (subscript) multiplied by the number on the periodic table. The ratios should be arranged in a way that allows for units to be cancelled.