The Replicase Enzyme of the SsRNA Phage Q $\beta$ Has Been Used by Scientists to Do Which of the Been

The replicase enzyme of the ssRNA phage Q $\beta$ has been used by scientists to do which of the following?

A) Synthesize RNA molecules from a DNA template.
B) Measure small amounts of target RNA molecules in a sample.
C) Measure the levels of pathogenic viruses in drinking water.
D) Amplify DNA molecules in a sample.
E) Fuse two pieces of RNA together.