A binding price ceiling on apartments (effective rent control) will:

(A) increase the quantity supplied of rental housing.
(B) decrease the quantity demanded of rental housing.
(C) create a greater quantity supplied of rental housing to be made available to renters.
(D) cause the quantity demanded to exceed the quantity supplied of rental housing.

D) cause the quantity demanded to exceed the quantity supplied of rental housing.

Explanation:

A price ceiling is a binding government regulation in which it puts a cap on the price landlords can charge tenants to rent their properties. If this happens, there could be a rapid significant increase in the demand of apartments. This would lead  to excess demand that the existing  supply cannot meet , creating a shortage. The property owners may also choose to not rent their apartment at that lower price driving the supply even lower.

increased production flexibility.

Explanation:

It is arguable that B2B e-commerce does not increase production flexibility because commerce generally bothers about sales, since it increases reach  to customers, guarantees better supplier and consumer management due to the amount of information available.

Production Flexibility on the other hand bothers on a company's capability in adjusting its production capacity to changes in customer preferences without raising its costs.  

Hence, the output of B2B e-commerce (knowledge of customer needs) can be an input into production flexibility, but the later is more a matter of an organisation's internal core competence than a benefit of B2B e-commerce.