Explanation:

- Option 1: Skilled on

- This is incorrect. We typically say "skilled at" or "skilled in."

- Option 2: Strong of

- This is incorrect. "Strong of" is not a common collocation. We use "strong in" or "strong at."

- Option 3: Experienced of

- This is incorrect. The correct phrase is "experienced in," when referring to a specific field or skill.

- Option 4: Experienced in

- This is the right choice. "Experienced in" is the correct collocation when talking about proficiency in a particular area.