What are the three challenges of a cell?

The cell must exchange materials with the environment across the surface membrane. An increase in size will result in a relatively greater increase in volume and mass than in surface area, so that the cell will lose effective exchange capacity. 

Ibelieve its a because an empirical formula usually has a ch in it your options are a or b

Heya dearfirst love doesn't matter what the it's just happen so we cannot say that minor in love with someone over 18 years old