What does the word Interim mean ?

at or during the same time : meanwhile The regulations are scheduled to go into effect next winter, and in the interim, we'll be working hard to make all of the appropriate changes.

interim means the intervening time can also mean temporary.

Explanation:

The minutes before the interim, I kept staring at the clock.

D. Higher costs due to customer support is not a benefit to smaller retailers of online shopping.  

Smaller retailers often incline themselves doing affordable business and save on cost as much as they can. Unlike large retailers, small retailers cannot afford to run a dedicated customer support service separately for their business online.

But looking at the trend of modern-day e-commerce, it becomes mandatory for them to dispense customer support service which doesn't prove to be very beneficial to the business.