RNA is synthesized in the 5' to 3' direction (from the point of view of the growing RNA transcript). Only one of the two DNA strands is transcribed. This strand is called the template strand, because it provides the template for ordering ...
The question deals with how to transcibe a short piece of DNA into RNA. The answer is not obvious at first and to determine the solution is a bit tricky. The solution answers the question fully and explains how the answer was determined. As well, a link to further reading is provided for additional study.