Mariana and Deion are collecting information for a marketing class project involving their client, the Humane Society. Neither one of them lives in the city where their university is located, and they do not have personal transportation. So$,$ Mariana and Deion write a survey asking about preferences in animal adoption and email it to members of their class. They are using a nonprobability sample that is also a $\_\_\_\_\_\_\_$ sample.

a$.$ judgement

b$.$ convenience