I dont know the answer sorry follow me for a follow back
I believe it's answer #3. Logically, at least.
You can test #1 through trial and error.
You can experiment #2 also through trial and error.
You cannot test #3 through trial and error, because that would be catastrophic.
You can test #4 through a survey and individual study and data collection.
P1/T1=P2/T2 Gal Lussac's Law
25 C= 298K (just add 273)
0 C= 273 k
6.00atm/298=P2/273
P2=5.50 atm
There are 16 hydrogen atoms