Select the option that can be used as a one-word substitute for the given group of words.
The act of killing one’s mother

Correct option is D

The option that can be used as a one-word substitute for the given group of words is (d) Matricide.
 Matricide is the act of killing one's mother, which is the same as the meaning given in the question.
Meanings of the other options:
 Regicide means the act of killing a king or queen.
 Homicide means the act of killing a human being.
 Uxoricide means the act of killing one's wife.