Concept:The word "surveillance" means close observation or monitoring. It follows a specific spelling pattern: "sur-" + "veillance".
Explanation:Check each option against the correct spelling "surveillance".
Option A: "Servillance" – The first part is "serv", not "sur". Incorrect.
Option B: "Survailance" – The "ai" after "v" is wrong; the correct sequence is "veil". Incorrect.
Option C: "Survilance" – The "i" after "v" is wrong; it should be "ei". Incorrect.
Option D: "Surveillance" – Matches the correct spelling. It has "sur", then "vei", then "llance". Correct.
Thus, only option D is correctly spelled.
Answer:Option D. Surveillance