Answer:
Most of the birds could already fly well (Gray 186).
Explanation:
Whenever citing any text in an academic or written work, it is mandatory to follow carefully how the various citations are done. There are different styles of in-text citations, on how and where one thing goes.
But most commonly, in-text citations are done with the name of the author/ authors and then followed by the page number in parenthesis (). Also, one major mistake and also a common confusion is the positioning of the period (.). "Periods (.)" are put right after the parenthesis, not before it.
Like, for example,
<em>Most of the birds could already fly well. (Gray 186)</em> is wrong in the placement of the 'period'. Also, the first two options are wrong as the name of the author is cited wrongly and instead used the name of the source.
Thus, the correct way of making in-text citation is-
<em>Most of the birds could already fly well (Gray 186).</em>