After excavating the site, archaeologists collect artifacts they've found. this process can be exhaustive(41) and time-consuming. artifacts must first be cleaned of dirt or other particles and then to catalog(42) numerically to keep track of each object.(43)

refer to number 43 in the passage and choose the best response below.

the best placement for the underlined portion would be:

where it is now.
after the word and.
after the word then.
after the word particles.