Identify ∪i=1[infinity]ai and ∩i=1[infinity]ai for the given ai, where i is a positive integer. ai = {i, i+1, i+2, ...}.
a) ∪i=1[infinity]ai = {1, 2, 3, ...}; ∩i=1[infinity]ai = { }
b) ∪i=1[infinity]ai = {1, 2, 3, ...}; ∩i=1[infinity]ai = {1}
c) ∪i=1[infinity]ai = { }; ∩i=1[infinity]ai = {1, 2, 3, ...}
d) ∪i=1[infinity]ai = { }; ∩i=1[infinity]ai = { }