An exeggutor question

Like in most cases, its ATK that affects CP the most, but which is the most important? I would say that it depends on how you gonna use it (attacker or defender) and if you value time or dmg before fainting more. But IMO Exeggutor has pretty balanced stats so everything is important.

Defense is its lowest stat, so a higher def IV will improve more the defensive ability of Exeggutor