Answer:
a. True
Step-by-step explanation:
A system may be sometimes casual, time invariant, memoryless, stable and linear in particular.
Thus the answer is true.
A system is casual when the output of the system at any time depends on the input only at the present time and in the past.
A system is said to be memoryless when the output for each of the independent variable at some given time is fully dependent on the input only at that particular time.
A system is linear when it satisfies the additivity and the homogeneity properties.
A system is called time invariant when the time shift in the output signal will result in the identical time shift of the output signal.
Thus a system can be time invariant, memoryless, linear, casual and stable.