16. Whose house is that? It's _____. A) Katies' B) Katie C) Katie and Jack's

Solution:

• The question asks 'Whose house is that?', indicating possession.
• Option A, 'Katies'', uses the possessive apostrophe correctly for a plural possessor (if there were multiple Katies, which is unlikely in this context) or an irregular plural. However, it's more commonly used for singular possessors ending in 's' where the apostrophe follows the 's', or for plural nouns where the apostrophe follows the 's'. If 'Katie' is a singular name, the possessive form is 'Katie's'.
• Option B, 'Katie', is the singular noun and does not show possession.
• Option C, 'Katie and Jack's', correctly shows joint possession by both Katie and Jack. The possessive 's' is placed after 'Jack' because it applies to both names collectively. This is the grammatically correct way to show joint possession by two individuals.
• Therefore, 'Katie and Jack's' is the most appropriate answer to indicate that the house belongs to both Katie and Jack.

Answer: C) Katie and Jack's