Best answer: C

Reasoning: Optical/radiographic density depends on how much radiation reaches the film or detector. Increasing tube current (mA) or kilovoltage (kVp) increases exposure, while greater object/thickness absorbs more x-rays and lowers density (Thunthy & Manson-Hing, 1978, PMID 278941; Duinkerke et al., 1978, PMID 273854). Changing the cone (beam) angulation alters image geometry and distortion but does not appreciably change the quantity of radiation hitting the receptor, so it has little effect on radiographic density.