Which group of words in this sentence is a dependant clause that contains a phrase?

Bearden was supporting young minority artists when he helped establish the Clinque
Gallery in 1969.
A. Bearden was supporting young minority artists
b. when he helped establish the Clinque
Gallery in 1969.
C. was supporting young minority artists when he helped
D establish the Clinque
Gallery in 1969.

Project information: the pythagorean theorem can be used in many real-world scenarios. the following is an example of real-word scenario where you will use the pythagorean theorem to find the missing piece. real-word scenario: a handyman needs to create triangular trusses to frame out the roof of a small shed. he knows the roof itself will be 9 feet tall and the length of each truss will be 14 feet. how long will the roof be from its highest to lowest point? part 1: the handyman created a drawing to provide a visual to solve this problem. below is his drawing. 1. part 2: solve the real-life scenario. show all your steps in answering the question and make sure you label your final answer correctly.