Idiom
X rather than Y

X and Y have to be parallel

During and immediately after the California gold rush, the way for a merchant to generate the most profit was to move a limited amount of scarce goods to San Francisco as quickly as possible, rather than to carry larger loads more slowly, determining the design of the clipper ship

The Bold and Underline have to be parallel


So Option has to start with "to"

only A and B

Now A has no clear antecedent "determining"

b) to carry larger loads more slowly, a situation that determined

Situation==> proper antecedent

Hope this helps

Karan

IMO B
During and immediately after the California gold rush, the way for a merchant to generate the most profit was to move a limited amount of scarce goods to San Francisco as quickly as possible, rather than to carry larger loads more slowly, determining the design of the clipper ship.

a) to carry larger loads more slowly, determining ---- determining antecedent is unclear - goods or speed or the whole situation
b) to carry larger loads more slowly, a situation that determined --- clearly refers to the situation
c) carry larger loads more slowly, which determined --- which has no proper referent
d) slowly carry larger loads which determined --- which has no proper referent
e) carrying larger loads more slowly, and this was a situation in determining --- and shouldn't preceeded with a comma here, was a situation in determinig is awkward and wordy