b
Given, current gain of \(CE\) amplifier \(\beta=69, \mathrm{I}_{\mathrm{E}}\) \(=7 \mathrm{mA}\)

or \(\quad \frac{\mathrm{I}_{\mathrm{C}}}{\mathrm{I}_{\mathrm{B}}}=69\)

We know that, \(\alpha=\frac{\beta}{1+\beta}=\frac{69}{70} \cdot \frac{\mathrm{I_C}}{\mathrm{I}_{\mathrm{E}}}\)

\(\mathrm{I}_{\mathrm{C}}=\mathrm{I}_{\mathrm{E}} \times \frac{69}{70}=\frac{\mathrm{69}}{70} \times 7\)

Collector current, \(I_{C}=6.9\, \mathrm{mA}\)