Let's do this answer choice by answer choice:

Out of a growing pride in the region's pre-automotive achievements have developed a committee for the preservation of Detroit's landmarks and artifacts that are creating monuments and museums across the city.

(A) have developed a committee for the preservation of Detroit's landmarks and artifacts that are creating

This is inverted sentence structure, where the verb comes before the subject. "A committee HAS developed..."

(B) has developed a committee for the preservation of Detroit's landmarks and artifacts that is creating

PERFECT!

(C) has developed a committee for the preservation of Detroit's landmarks and artifacts that create

Subject-verb agreement: a "committee that CREATES".

(D) have developed a committee for the preservation of Detroit's landmarks and artifacts that are creating

A committee HAS developed...
Subject-verb agreement: "a committee that IS creating".

(E) have developed a committee for the preservation of Detroit's landmarks and artifacts that create

A committee HAS developed...
Subject-verb agreement: a "committee that CREATES".

By the way, I don't love the answer to this one, because it's always iffy to have a relative pronoun touching something it isn't really modifying ("artifacts"). But there's no better option here, so we have to assume it's modifying the WHOLE compound noun ("a committee for the preservation of Detroit's landmarks and artifacts")

Hope that helps!

-t