Other than yourself, of course! Random gaffot #879843 knows best.
Because there is no neutral course of action, let's go over the options one more time:
1) Hormone blockers allow a child time to make a choice. Not every kid needs this option, of course, but one expressing strong symptoms of a certain clinically recognized disorder called "gender dysphoria" probably does!
2) Natural puberty forces (!) a child to undergo a change that they may or may not want - at this point, things indicate that they do not want! - and will most likely cause a difficult-to-reverse and excruciating period at the most important developmental age in a human being's life, as they grow into the person they are...or, you know, are forced to become something they know they aren't.
But, you know, who gives a shit about the kid. Lying little shit just wants attention, amirite, GAF?