Scientific language
often employs common words in ways that clash with the general usage, such as "temperate"; this term is generally used to refer to mild, pleasant weather, but climatologists use it in regions where summers are hot, winters are harsh, and extreme climatic variation.
First round of Elimination " with the general usage vs with their general usgae"
A. often employs common words in ways that clash with
the general usage, such as "temperate"; this term is generally used to refer to mild, pleasant weather, but climatologists use it in regions where summers are hot, winters are harsh
B. often employs common words in ways that clash with
their general usage; for instance, the term "temperate," which in general usage refers to mild, pleasant weather, is used by climatologists to describe regions with hot summers, harsh winters
C. employs common words often and in ways that clash
with general usage; specifically, the term "temperate" is generally used for mild, pleasant weather, and by climatologists to refer to regions with hot summers, harsh winters
D. employs common words in ways that often clash
with general usage, as when climatologists use "temperate," a term generally used to refer to mild, pleasant weather, to characterize regions where summers are hot, winters are harsh
E. employs common words in ways that often clash
with their general usage; climatologists in particular use the term "temperate" -- which generally refers to mild, pleasant weather -- in describing regions with hot summers and harsh winters
"Their" specifies with what their referring to "common words" as general usage and common words mean one in the same thing. It can't refer to scientific language because of its meaning and because their is plural and scientific language is singular. So eliminate
"A" "C" "D"Second round of elimination " which in general usage" vs " generally refers to"
B. often employs common words in ways that clash with their general usage; for instance, the term "temperate,"
which in general usage refers to mild, pleasant weather, is used by climatologists to describe regions with hot summers, harsh winters
E. employs common words in ways that often clash with their general usage; climatologists in particular use the term "temperate" --
which generally refers to mild, pleasant weather -- in describing regions with hot summers and harsh winters
"In general usage" because we need to specify where is this term used and what it is referring to.
So B. Another point is hot summer and harsh winters, and extreme climatic variation. Two times " and " is used. Which does not support parallelism.