Maximum displacement: +- 14
The purpose of sending troops to Vietnam was to prevent Vietnam from becoming a communist state- much like the neighbouring China did. The US feared the domino effect in which more and more neighbouring states become communist.
This policy was called the containment policy (the answer is B) - communism were to be contained.
Replacing <em>F</em> with <em>F</em> + 1 gives
5/9 (<em>F</em> + 1 - 32) = 5/9 (<em>F</em> - 32) + 5/9 = <em>C</em> + 5/9
so a temperature increase of 1º F translates to a 5/9º increase in Celsius, so I is true.
Replacing <em>F</em> with <em>F</em> + 5/9 gives
5/9 (<em>F</em> + 5/9 - 32) = 5/9 (<em>F</em> - 32) + (5/9)² = <em>C</em> + 25/81
so increasing the temperature by 5/9º F amounts to a 25/81º increase in Celsius, so III is false.
Solve for <em>F</em> in terms of <em>C</em> :
<em>F</em> = 9/5 <em>C</em> + 32
Replacing <em>C</em> with <em>C</em> + 1 gives
9/5 (<em>C</em> + 1) + 32 = 9/5 <em>C</em> + 32 + 9/5 = <em>F</em> + 9/5
and 9/5 = 1.8, so a 1º C increase translates to a 1.8º F increase, so II is also true and the answer is D.
You should not leave it out longer than 1/2