viable

"You're right! "Viable" is an adjective, not a noun. My apologies!

Here's a simple sentence using "viable" correctly, following your guidelines:

The doctor confirmed the baby was viable at 24 weeks of gestation. "

"The premature baby was considered viable after a week in the neonatal intensive care unit. "

"A later start time for school is a viable option for improving student attendance. "

"The new seeds were viable, so the gardener planted them in the garden. "