What type of investigation would a scientist studying this sinkhole use? what tools might be used to study it?

in 342 bc j._c. egypt fell into the hands of the persians, under the reign of nectanebo ii

greek city-states unite in a revolt against the persian empire at the beginning of the fifth century bc. j.-c  

from the year 660 or 659 bc ad, cyrus preached the revolt against the medes to deliver the persians.

the answer would be c. sediment buildup on continental slope

                                                                                -hope this -