Which of the following sentences is correctly punctuated regarding a wedding anniversary celebration?

The sentence "To celebrate my parents' 50th wedding anniversary..." is correctly punctuated because it properly uses the possessive form for "parents." When referring to more than one parent (in this case, both mother and father), the plural form "parents" requires an apostrophe placed after the "s" to indicate that the anniversary belongs to both parents. This makes the phrase possessive and grammatically correct.

The context of the other options highlights common pitfalls in possessive punctuation. The first option incorrectly uses "parent's," which would imply that the anniversary belongs to only one parent. The other choices differ slightly but can introduce different issues; one of them does not specify the wedding aspect, which changes its meaning, while the other might misplace punctuation, thus altering clarity. The correct use of possessive apostrophe ensures clarity and accurately reflects the relationship being described.