The microbiology laboratory report for mrs. wallace's urine culture lists eight antibiotics, five of which are followed by the letter "s." this means that these antibiotics

Antibiogram (Drug susceptibility testing (DST)) is a laboratory test to determine the susceptibility of a bacterium to different antibiotics. Indeed, many bacteria have become, over time, resistant to antibiotics.

The "S" that follows the name of the antibiotic in the antibiogram report means that the bacteria are sensitive to that molecule and can be easily killed.

In the antibiogram you can find other letters following the antibiotics:
"R" means the bacteria is resistant to that molecule.
"I" means intermediate, between sensitive and resistant.
and finally "NT" which means not tested

Ithink the answer is d.