Regulation of the Ci (Cubitus interruptus) protein in the Hedgehog signaling pathway is reminiscent of that of β-catenin in the Wnt pathway. Which of the following features is shared among these two proteins?

A) Both proteins are ubiquitylated when the signal (Hedgehog or Wnt) is present.
B) Both proteins are able to enter the nucleus only in the absence of the signal.
C) Both proteins can be phosphorylated by GSK3 and CK1 in the absence of the signal.
D) Both proteins are fully degraded by the proteasome in the absence of the signal.
E) None of the above.