Identify the correct substitution for the underlined portion of the sentence below.
To prepare these muffins start by putting two ripe bananas a cup of walnuts, 2 cups of flour, two eggs, 1 cup of sugar in a bowl.
To prepare these muffins start by putting two ripe bananas a cup of walnuts, 2 cups of flour, two eggs, 1 cup of sugar in a bowl.