Tessellate S.T.E.M.S (2019) - Physics - Category C - Problem Set 1 - Objective Problem 2

Which of the following statements are true:

a) If $A$ and $B$ are simultaneous events, there exists an inertial frame for which the events are not simultaneous.

b )If $A$ and $B$ are not simultaneous events, there exists an inertial frame in which events are simultaneous.

c ) If event $A$ has caused the event $B$ , there can't be any observer for whom events happened simultaneously.

d) None of the above