Which of the following is a precaution which must be followed while performing assays?

• A. It should be ensured that once steady state is reached, the rate of reaction is constant over a period of interest and proportional to the amount of enzyme added
• B. The response should be accurate, reproducible, precise, linear and free from electrical noise
• C. The probe must be tiny and biocompatible
• D. It should be cheap, small portable and capable of being used by semi-skilled operators