I don't understand #1. I don't understand how anyone can call releasing a beta particle "as a form of nuclear fission". It may OCCUR during nuclear fission but in my mind it is definitely NOT a "form" of nuclear fission. The same is true for alpha decay. My best guess is that you picked the teacher's choice.
2 and 3 and 6 are incorrect.
Here is the way to do these decay problems. You want the mass numbers to add up on both sides AND the atomic numbers to add up on both sides.
238_92 U + 4_2 He -> ____ + 1_0
So 238 + 4 = x + 1 so x must be what? Did you say 241?
92 + 2 = y + 0 so y must be what? Did you say 94?
Now look on the periodic table to see what element 94 is? I think that's Pu with a mass number of 241. Piece of cake? That makes your choice c??
Sorry I was so late in getting back to you; however, my company just left about two hours ago.