For centuries, people on sea voyages

[NandishSS]

For centuries, people on sea voyages washed their clothes by placing the dirty laundry in a strong cloth bag, then toss it overboard, and let the ship drag the bag for hours.

A. then toss it overboard, and let
B. then toss them overboard, and they let
C. tossing it overboard, and letting
D. tossing them overboard, and let
E. tossing it overboard, and let

OA:C

Source: GMATPrep

Why option D is wrong is it because tossing refers to bag so it is right?

[melguy]

For centuries, people on sea voyages washed their clothes by placing the dirty laundry in a strong cloth bag, then toss it overboard, and let the ship drag the bag for hours.

A. then toss it overboard, and let
B. then toss them overboard, and they let
C. tossing it overboard, and letting
D. tossing them overboard, and let
E. tossing it overboard, and let

OA:C

Source: GMATPrep

Why option D is wrong is it because tossing refers to bag so it is right?

The clothes were placed in a bag. Bag is singular and them cannot be used for a bag.

In SC the best thing you could do is to eliminate the wrong options and not try and justify the that a certain answer is correct.

[fiza gupta]

pronoun and parallelism tested

tossing what -> "a bag" -> it should be used not them
B and D are eliminated

by placing, tossing , and letting -> all three action should be in parallel
SO C