An invalid study may have all of the following problems except a. poorly designed test questions b. insufficient data c. variables that relate to the topic d. interference of unrecognized variables

post-impressionism is a predominantly french art movement that developed roughly between 1886 and 1905, from the last impressionist exhibition to the birth of fauvism. post-impressionism emerged as a reaction against impressionists' concern for the naturalistic depiction of light and colour.

explanation:

the answer to your question is b