Most bacteria:
a. do not immediately increase in number when placed in a culture
b. exhibit synchronous growth under natural conditions
c. divide when a small new cell develops from the surface of an existing cell
d. immediately begin to divide when placed in a culture

Option A, do not immediately increase in number when placed in a culture

Explanation:

When a bacteria is placed in a culture, it does not start reproducing immediately. There are four growth phases of  bacterial population in a given culture. During the lag phase, the bacteria becomes active and increases its cell size. After the lag phase, the bacterial cell enters into the log phase and start dividing thereby increasing its population in a logarithmic fashion until it reaches a stage where accumulated toxic products reduces the rate of cell growth and hence the bacterial population

Thus, option A is correct