Answer:
B. ∃x (x2<1)
Step-by-step explanation:
When we take X = 0 and Placing it in each option as follow
A.
∃x (3x=1)
∃x (3(0)=1)
∃x (0=1)
Which is not true
B.
∃x (x2<1)
∃x ((0)2<1)
∃x (0<1)
Which is true
C.
∀x (x2=1)
∀x ((0)2=1)
∀x (0=1)
Which is not true
D.
∃x (x2<0)
∃x ((0)2<0)
∃x (0<0)
Which is not true.