How Is It Possible for Single-Stranded RNA to Fold into Complex

Multiple Choice

How is it possible for single-stranded RNA to fold into complex shapes?

A) Phosphodiester linkages form between the phosphate and the sugar ribose.
B) Internal base pairings occur-adenine with uracil, and cytosine with guanine.
C) Uracil's methyl group binds to adenine, coiling the molecule.
D) The single strand "twists" around itself.
E) The RNA binds to proteins, creating a conformation (three-dimensional shape) .