Which of the following is not an example of a trade-off?
a. Flowers that produce more nectar are likely to receive more visits from pollinators.
b. Bacteria with genes that confer resistance to antibiotics grow more slowly than those that are susceptible to antibiotics.
c. A plant that invests in above ground growth will have smaller roots.
d. Mosquito fish that are able to swim very rapidly are not able to swim for long periods of time.
e. Frogs that sing elaborate courtship songs are more likely to attract mates and predators.