<p>Companies that often require managers to attend meetings in different countries can save expenses on airfare <u>through</u> video conference calls, which allow for international meetings without leaving the office.</p>
<p>The correct answer is (<strong>B) through</strong>.</p>
<p>In this context, the phrase "save expenses on airfare" means to reduce or avoid the costs of air travel. The preposition "through" is used to indicate the means or method by which something is accomplished. In this case, the method of saving expenses on airfare is by using video conference calls instead of physically traveling to different countries for meetings.</p>
<p>The other options are incorrect:</p>
<p>(A) "Throughout" is a preposition that means during or throughout a period of time. It does not convey the idea of saving expenses on airfare.</p>
<p>(C) "Thorough" is an adjective that means complete or comprehensive. It does not fit in the context of saving expenses on airfare.</p>
<p>(D) "Thought" is the past tense and past participle of the verb "think." It is not appropriate in this context.</p>