In this question, we have to determine which compound has the greatest number of elements in its composition. Since we have one mol of all 4 compounds, we have the same number of particles or atoms, but in terms of elements that are composing these compounds we will have some differences
CO2, we have 3 atoms
C22H46, in this hydrocarbon, we have 68 elements present
C6H12O6, we have 24 atoms in this case of Glucose
CH4, we have 5 elements
Therefore the compound with the greatest number of elements will be C22H46, letter B
