In the Oregon Treaty with Britain in 1846, the Northern $\degree$

In the Oregon treaty with Britain in 1846, the northern boundary of the United States was established to the Pacific Ocean along the line of

A) 42 $\degree$ .
B) 52 $\degree$ 40'.
C) 54 $\degree$ 40'.
D) 36 $\degree$ 30'.
E) 49 $\degree$ .