The answer is <u>c</u><u>.</u><u> </u><u>s</u><u>o</u><u>l</u><u>i</u><u>d</u><u>s</u>
<h2>EXPLANATION:</h2>
Sound travels fastest through solids. This is because molecules in a solid medium are much closer together than those in liquid or gas, allowing sound waves to travel more quickly through it.
Montevideo, Uruguay (35°S) had the longest day on June 21, 2019 during the Summer Solistics when the sun is directly over the tropic of cancer which is on latitude 23.5 degrees North. Montevideo is closest in latitude to this point among the options and as such will experience a longer day compared to the other options.