【单选题】Which of the following is a reasonable way to explain the ability of enhancers to act at a distance?
A.
The activator binds to an enhancer, changing the supercoiling state of the DNA and opening up the promoter to general transcription factors.
B.
The activator binds to an enhancer, slides along the DNA until it encounters the promoter, and activates transcription.
C.
An activator binds to an enhancer, creating loops in the DNA, which leads to the interaction of proteins at the promoter and activation of transcription.
D.
An activator binds to an enhancer and a downstream segment to form a loop, which causes the protein to track toward the promoter and activate transcription.
【单选题】It's a good idea to include some information about the context, a task statement and perhaps a purpose statement in the _________________ of a technical memo.