"If you can save up enough babysitting money to pay for half of the plane ticket, I will let you go," she replied. I was thrilled!". In the first case, after the auxiliary verb "can", it follows an infinitive verb. That is why the options "was save," "am saved," "was saved," and "am" are not correct.
In the second case, "thrilled" is an adjective. The verb "to be" alone goes before an adjective to describe the way the person is feeling. That is why "save," "was save," "am saved," and "was saved" are not correct.