Which is the best meaning for impending as it is used in the selected sentence?

Read the speech from the play the importance of being earnest. algernon. you have invented a very useful younger brother called ernest, in order that you may be able to come up to town as often as you like. i have invented an invaluable permanent invalid called bunbury, in order that i may be able to go down into the country whenever i choose. bunbury is perfectly invaluable. if it wasn’t for bunbury’s extraordinary bad health, for instance, i wouldn’t be able to dine with you at willis’s to-night, for i have been really engaged to aunt augusta for more than a week. which responses clearly describe how a student who didn’t know the word invaluable could determine its meaning?