disadvantage of group intelligence tests include that

a. all test taker must wait until all registered individuals arrive
b. proctors are often inconsistent and allow some test takers a longer time to respond or to take testing breaks
c. some test taker talk to themselves and disturb others
d. some test takers are more motivated to perform at their highest level in one one testing situation

i think its D
but not sure

I agree.

Assuming that you mean "one on one," I agree too.

To determine the correct answer, let's analyze each option:

a. "All test takers must wait until all registered individuals arrive." This statement suggests that group intelligence tests may involve delays if some participants are late or absent. While this may be a minor inconvenience, it is not necessarily a significant disadvantage of group intelligence tests.

b. "Proctors are often inconsistent and allow some test takers a longer time to respond or to take testing breaks." This option suggests that inconsistencies in time allowances or breaks might occur during group intelligence tests. This could potentially create an unfair testing environment, affecting the reliability and validity of the test results.

c. "Some test takers talk to themselves and disturb others." This option highlights a potential issue with group intelligence tests, as distractions from other participants could hinder concentration and affect performance.

d. "Some test takers are more motivated to perform at their highest level in one-on-one testing situations." This option implies that individual testing situations may enhance motivation and allow some participants to perform better than they would in a group setting.

Considering the options, it seems that option D is the most appropriate choice. It identifies a disadvantage of group intelligence tests, as the presence of others might not provide the same level of motivation for all test takers as individual testing situations would. Thus, option D is likely the correct answer.