Adj

Question 1

Able to exist, perform as intended or succeed

Answer 1

Viable
Your brand is seen as a valuable and viable choice for customers

Question 2

Useful or helpful

Answer 2

Worthwhile

Question 3

without energy and effort:

Answer 3

Lackluster
To shift your focus away from lackluster activities

Question 4

Impossible to prove wrong

Answer 4

Irrefutable
Irrefutable argument
The evidence was irrefutable