38. GTPases have a slow nucleotide hydrolysis rate. Which of the following statements about GTPases is TRUE? (A) Guanine nucleotide exchange factor (GEF) proteins promote GTP dissociation from GTPases. (B) Ras GTPase activating proteins (GAP) reduce the kcat of Ras.(C)G protein coupled receptor (GPCR) proteins prefer binding to the GTP- bound Gapy. (D) Regulator ofG protein signaling (RGS) proteins stabilize the transition state of Ga to enhance GTP hydrolysis. (E) Ras GTPase activating proteins (GAP) increase the Kn of Ras.