I think that the answer is D
The answer could actually be "climb" or "was climbing," but traditionally should be "climb." Hope this helps :)
<span>As it turns out, Mrs. Winterbottom leaves to reconnect with a son she gave up for adoption before she married Mr. Winterbottom. She never told anyone about this son for fear of not seeming "respectable." She is very worried about being "respectable," perhaps because Mr. Winterbottom cares so much about being respectable, too.</span>
