Select the option that can be used as a one-word substitute for the given group of words.
The patronage bestowed in consideration of family relationships and not of merit.

The correct answer is Nepotism.

Let us break down the meanings of the given options to understand why Nepotism is the correct one-word substitute:
1. Nepotism: This refers to the practice among those with power or influence of favoring relatives, friends, or associates, especially by giving them jobs or privileges, regardless of their merit. This perfectly matches the definition: "The patronage bestowed in consideration of family relationships and not of merit."
2. Egotism: The practice of talking and thinking about oneself excessively because of an undue sense of self-importance.
3. Mannerism: A habitual gesture or way of speaking or behaving; an idiosyncrasy.
4. Neologism: A newly coined word or expression, or a new meaning for an established word.

Therefore, the word that replaces the given group of words is Nepotism.