Answer:
The correct answer option is a) Allusion.
Step-by-step explanation:
Allusion is a figure of speech which is an indirect way of expression in which something is called and talked about only in the mind without mentioning it specifically.
Here allusion is the literary term which is used in the given quote as somebody is making reference indirectly and does not mention anything specifically.
The mentioned quote does not mention who said it and to whom.