In addition to E. coli, a risk factor for development of pyelonephritis is: a. urinary retention and reflux. b. nephrotic syndrome. c. glomerulonephritis. d. respiratory disease.

One of the factors for the development of pyelonephritis, in addition to E. coli, is urinary retention and reflux (option a).

Explanation:

Pyelonephritis is an infection of the upper urinary tract caused by bacteria in the urine, such as Escherichia coli.

Under normal conditions, urine in the urinary bladder is aseptic, that is, without bacteria.  The presence of bacteria in the urine indicates a urinary infection.

Urinary retention is the limitation of the expulsion of urine from the bladder. This promotes:

The result of urinary retention and reflux - when bacteria are present - is an infection in the upper urinary tract, called pyelonephritis.

Learn more:

Urinary tract infection link