Which type of enzyme is responsible for activating subunit A?A.EndonucleaseB.ExonucleaseC.RibonucleaseD.Protease

The question doesn't provide enough context to determine which type of enzyme is responsible for activating subunit A. The activation of subunit A could be dependent on any of these enzymes, depending on the specific biological process or pathway being referred to.

Endonucleases, exonucleases, and ribonucleases are all involved in the processing of nucleic acids (DNA and RNA), while proteases are involved in the processing of proteins. If subunit A is a part of a nucleic acid, then it could be activated by an endonuclease, exonuclease, or ribonuclease. If subunit A is a part of a protein, then it could be activated by a protease.

Without more information, it's impossible to definitively answer this question.