In a common base circuit at VC = 3V, a change in emitter current from 12.0 mA to 18.5 mA produces a change in collector current from 11.8 to 17.4 mA. The current gain will be:

0.9521 0.8615 0.7351 None of these

0.8615

$α=(\frac{ΔI_c}{ΔI_e})_{V_e}=\frac{17.4-11.8}{18.5-12.0}=\frac{5.6}{6.5}=0.8615$