Harry hess used new technologies made available in the 1950s to observe and measure

a. seafloor spreading
b. sediment deposition rates
c. global climate variations
d. rates of tectonic plate movement

A) seafloor spreading

Explanation:

According to the theory of Harry Hess, seafloor spreading hypothesis is described as formation of oceanic crust at sides of submarines zones and ridges of mountains and then tends to spread away from that surface.

Other options are incorrect because tectonic plate movement,sediment deposition measure and global climate variation is not expressed through theory of Harry Hess.Thus, the correct option is option(A).

idk why hjggjhjkhj

silt loam

hope this