The exposure factors used at an oral health care facility are: 10 mA, 0.9 sec, 70 kVp, and 16-in. (41-cm) target–image receptor distance. The radiographer increases the mA to 15, but leaves the kVp...

The exposure factors used at an oral health care facility are: 10 mA, 0.9 sec, 70 kVp, and 16-in. (41-cm) target–image receptor distance. The radiographer increases the mA to 15, but leaves the kVp and target–image receptor distance constant. To maintain identical image density, what should the new exposure time be?

a. 0.3

b. 0.6

c. 1.2

d. 1.8