The most lasting achievement of Alexander the Great<span> was the spread of Koine Greek throughout the Mediterranean world and the Middle East. A common language became spoken from Spain to India.</span>
Am irregular verb means that the different forms of the verb will differ and will not follow a regular pattern,
The pattern here should be:
I VERB, I VERB-ed, I will VERB
the first three options follow this pattern, so they are regular,
the correct answer is D. it is irregular: the past tense form is irregular.
C. It legitimized the power of the national government over states