Unfortunately, it's wrong as a logical argument. The problem is the completely unfounded assumption that there is only one best option. What makes you think that there is only one best option? There could be millions of options with equivalent benevolence effect. There's no reason to assume this, nor any evidence to warrant it.

I'm not Christian, myself; I'm not defending Christianity. It's just the argument itself is flawed.

The argument assumes that God is omnibenevolent; which is patently not the case, even in Christianity. Does not God smite wrongdoers, like the people of Sodom and Gomorrah? He's not being too benevolent to them there ...