engagement

The total fee income from LV Fones is 16% of the total fees for the audit firm. if the fees for audit and recurring work exceed 15% then there is a self-interest threat.

steps to avoid the threat:
1) Condiser whether the appearance of independence will still be met if the tax and audit work is retained.
2)No further work should be accepted in the current year from the client, and it might be advisable to perform external quality control reviews.
3) consider resigning from either the tax or audit engagement.

my doubts:
who are engagement partners? i guess they refer to external auditor, i was confused by the term partner.

examiner talks about tax and audit engagement, what he is referring to tax here? i guess it is tax advice. or it may be something else.

examiner advises no further work to accept but consider another further work “external quality control reviews”. what is this review? why he is advising to do this?