You are provided with a bacterial culture (generation time of 30 min ) in exponential (logarithmic) growth phase. You transferred an aliquot of this culture to a fresh medium, which now contains $3.2 \times 10^6$ cells/millilitre. Considering that this culture does not exhibit a lag phase, and growth conditions remain unchanged, the cells/millilitre that you would obtain after 1.5 hours of incubation is ____.

• A

  $10 .5 \times 10^7$
• Correct answer
  B

  $2.56 \times 10^7$
• C

  $1.28 \times 10^7$
• D

  $3.20 \times 10^7$

Hence, the correct answer is option: 'B'.