Answer:
The relation that denotes the condition:
"The day is Tuesday or Thursday if and only if she comes to work” is given by:
p∨q↔r
Hence, option D is true.
Step-by-step explanation:
Let p: The day is Tuesday.
q: The day is Thursday.
r: She comes to work.
the day is Tuesday or Thursday is denoted by: p∨q
Hence the condition which represents that "The day is Tuesday or Thursday if and only if she comes to work”
is: p∨q↔r