Johnson Controls' implemented a policy that women who are pregnant or who are capable of bearing children would not be placed into jobs involving lead exposure. In April 1984, employees filed a class action lawsuit challenging Johnson Controls' fetal-protection policy as sex discrimination that violated Title VII of the Civil Rights Act of 1964. Among the individual plaintiffs were Mary Craig, who had chosen to be sterilized to avoid losing her job; Elsie Nason, a fifty-year-old divorcee, who had suffered a loss in compensation when she was transferred out of a job that exposed her to lead; and Donald Penney, who had been denied a request for a leave of absence for the purpose of lowering his lead level because he intended to become a father. Discuss whether the plaintiffs have a valid cause of action?