Rearrange the parts of the sentence in correct order.
As a result of greater competition
P: while others are contracting
Q: in the US computer industry
R: some computer companies are expanding
Greater competition must be explained as to competition regarding or in what? Q satisfies this criterion and therefore, Q is first. Rule out 1) and 3). Note how P and R state contrasting conditions (expanding-contracting). Clearly, others will come after some. (e.g. A, B, and others). Option 2) QRP is the correct answer.
As a result of greater competition in the US computer industry, some computer companies are expanding while others are contracting.