Which statement about maintaining accurate and complete data is true?

Question $27$ options:

a$)$

Eliminating all "bad data" is a reasonable goal, even on a limited budget.

b$)$

The only source of "bad data" is user data$-$entry errors.

c$)$

Data enhancement techniques can fully substitute for data cleansing.

d$)$

Data cleansing may involve standardizing data.