doesn't 'Яка' translate to 'which' more than 'what'?
It can translate both. I believe both are correct as translations of this sentence.
Without a context "яка" translates more to "what" than to "which." If I had a predefined selection of commands in the context, than it would be more a "which." In the end, I would accept both translations.
Which is more accurate, even if colloquially native speakers often use what.