A decrease in kilovoltage and an increase in milliampere-seconds will:

A decrease in kilovoltage (kV) while increasing milliampere-seconds (mAs) results in increased receptor exposure. This occurs because mAs determines the total quantity of x-rays produced during the exposure; therefore, increasing mAs will enhance the number of photons reaching the receptor.

When kilovoltage decreases, it reduces the energy of the x-ray photons, which might compromise the penetration ability of the x-rays through denser body tissues. However, if the mAs is significantly increased to compensate for this lower energy, it can lead to a sufficient number of photons reaching the receptor, resulting in a higher exposure level.

In terms of image quality, while kV influences contrast and penetration power, this scenario may still retain adequate image quality if mAs is increased enough to provide adequate density. However, increasing mAs does not negate the effects of decreased kV on contrast and detail resolution. Thus, it can be argued that receptor exposure increases, while there may be no significant impact on overall image quality in terms of exposure levels.

Therefore, the correct understanding is that the combination of decreased kV with increased mAs will improve receptor exposure, making the statement valid.