Answer:
A. the greater shortage an effective price ceiling will create.
Explanation:
Supply / demand price elasticity measures the sensitivity of supply / demand to changes in the price of the good. Thus, if supply / demand for the good is elastic, it is assumed that slight price changes will drastically affect supply / demand for the good. This means that price changes will cause supply / demand shortages for the good, so that a ceiling price will be set so that demand / supply for the good will be maintained.