Which sentence best summarizes the obstacles scientists faced when trying to grow cells before hela? answer choices for the above question
a. scientists were not able to get permission from patients to grow their cells in the lab, so there was not enough cell tissue to do their experiments.
b. scientists struggled to find the right medium for growing cells, and they couldnt keep the cells alive.
c. scientists were unable to keep the cells from growing too fast so that they overflowed into their other experiments and contaminated the entire lab.
d. scientists didnt understand how a cell worked, so they didnt know that it needed to be fed in order to keep growing.
