The correct answer is option A ("For example").
When supporting any kind of argument, presenting evidence is always a great way of strengthening the reasoning for backing up a certain position. T<u>he phrase </u><u>"for example"</u><u> is commonly found as a way to introduce or link factual evidence to a previously stated argument.</u>
"Similarly" or "on the other hand" would be most commonly used to establish a comparisson; while "however" would point towards a counter-argument.
Hope this helps!
B.
The phrase "whistle-like" should be separated by a hyphen. <span />
I'm pretty sure its the second option
