18. Why would researchers choose a double-blind study? O To prevent anyone from treating subjects in a way that changes their response

O To prevent researchers from knowing the results of a study after it is over

O To prevent subjects from choosing placebo

O Researchers do not use double-blind studies anymore

d

step-by-step explanation:

by observation, we can see that the the graph is simply the graph of y = |x| that has been shifted 4 units downwards and 3 units to the left.

we can recognize in choice d :

y = | x + 3 |   - 4 (rewriting in general form)

y = | x - (- 3) |   - 4

the "-4 " term means   that the graph has been shifted by 4 units in the negative y direction

the "-3 " term means   that the graph has been shifted by 3 units in the negative x direction

this matches our observation of the graph described above.

2

step-by-step explanation: