The first thing you should know is that acceleration is a vector, therefore, it has magnitude, and direction.
By definition, we have that the vector acceleration is given by:

Where,
dv/dt: derived from the velocity vector with respect to time,
Therefore, the units of the vector acceleration are:


The symbol of acceleration is:

Answer:
The statements about acceleration that are true are:
a. the si units of acceleration are m/s2.
b. for acceleration, you must have a number, a unit, and a direction.
d. the symbol for acceleration is (True, only if the symbol is the same as above)