In a river, large boulders are transported by
a. solution
b. traction
c. suspension
d. abrasion
which answer choice is the correct one? you.

B. Traction

Traction is a geological process in which a mechanical force transports larger and heavier rocks by sliding and rolling along the substratum. Traction occurs by water erosion. It results in the movement or transportation of large rocks stones or boulders, which are otherwise settled at the bottom, by the force exerted by the water current. These rocks, stones or boulders gets displaced from their sites and attains a rolling movement due to fast flowing water current.  

lysosome is this part of the cell is surrounded by a very thick outer membrane to protect the rest of the cell from its strong enzymes.