How would you count this measure?
A. 1-2,3-4,
B. 1,2-3,4
C. 1,2,3,4,
D. 1-3,4

Can you please tell me the time signature?

It depends on what type of third separates the three notes.for example: if you have two mayor thirds is an "aumented chord"if you have two minor thirds is an "diminued chord"if you have one mayor first and then one minor is a "mayor chord"and inverted is a "minor chord"