How did Alexander the Great constant exposure to war affected his ambitions and strategies

From his accession Alexander had set his mind on the Persian expedition. He had grown up to the idea. Moreover, he needed the wealth of Persia if he was to maintain the army built by Philip and pay off the 500 talents he owed. The exploits of the Ten Thousand, Greek soldiers of fortune, and of Agesilaus of Sparta, in successfully campaigning in Persian territory had revealed the vulnerability of the Persian empire. With a good cavalry force Alexander could expect to defeat any Persian army. In spring 334 he crossed the Dardanelles, leaving Antipater, who had already faithfully served his father, as his deputy in Europe with over 13,000 men; he himself commanded about 30,000 foot and over 5,000 cavalry, of whom nearly 14,000 were Macedonians and about 7,000 allies sent by the Greek League.

Ibelieve the correct answer is d.