A Titan IV launches a spacecraft due south from Vandenburg AFB (34.6° N latitude, 120.6° W longitude). What's the most northerly point (latitude) the spacecraft can view directly below it on any orbit?

the inclination and highest latitude reached is 90°.

Explanation:

given data

launches a spacecraft due south

location =  AFB (34.6° N latitude, 120.6° W longitude)

solution            

The highest latitude of any spacecraft is equal to its inclination.

Since that the launch of the spacecraft "due to  South"

the inclination and highest latitude reached is 90°.

answer at the divergent plate boundary in the middle of the ocean;