Which phase of drug testing determines whether the drug produced the desired effect?

In phase contrast microscopy, the function of the phase ring is to:

a. Direct light through its open circular area b. Retard the wavelength of deflected light c. Project the beam of light onto the sample d. Diffract the light from the condenser

When radiation sources are delivered to the OR, each needle, seed, or capsule must be counted by the surgeon with the radiation therapist and that number is recorded

Indicate whether the statement is true or false.