Indicate Whether Each of the Following Descriptions Better Matches the ATF6

Short Answer

Indicate whether each of the following descriptions better matches the ATF6 (A), the IRE1 (I), or the PERK (P) branch of the ER unfolded protein response. Your answer would be a four-letter string composed of letters A, I, and P only, e.g. APII.
( ) It involves a noncanonical cytoplasmic splicing process.
( ) Its sensor is a latent transcription regulator.
( ) It involves regulated proteolysis of the sensor protein in the Golgi apparatus.
( ) Its sensor bears both kinase and endoribonuclease activities.