Correct Option: B

When both the substrates are present in a batch bioreactor, microbial cells do not consume both substrates simultaneously or additively but instead grow on the sugars sequentially. The sequential consumption results in an interesting pattern of the cells first consuming one preferred substrate and then after an intermediate lag phase, consuming the remaining less preferred substrate. That is, the less preferred substrate is not utilized until the preferred substrate is completely consumed and is no longer available in the growth medium. This sequential utilization of two substrates in batch cultures has been observed in numerous experiments by Monod, who has termed this phenomenon as the "diauxic pattern of growth". It has multiple lag phases. ​