Final answer:
The acceptable level of activity on a wipe test would likely be less than 1 nCi or less than 5 nCi, considering the sensitivity of contamination regulations and safety practices.
Step-by-step explanation:
The acceptable amount of activity on a wipe test for a sealed source varies depending on the regulations of the country and the specific radioactive material. However, if we look at the context provided, the levels mentioned (nanoCuries and microCuries) are units of radioactivity measurement. A nanoCurie (nCi) is 1 billionth of a Curie, while a microCurie (uCi) is 1 millionth of a Curie. Typically, an acceptable limit for contamination would be in the nCi range, so options B (less than 1 nCi) and C (less than 5 nCi) might be viable depending on strictness of regulations. Option D (less than 1 uCi) is much higher and less likely to be considered an acceptable level of contamination for a wipe test. Considering the conversion between units, where 1 Ci = 3.7x1010 decays per second, we can infer that an acceptable level of activity on a wipe test would likely be less than 1 nCi or less than 5 nCi, options B or C.