Which of the following is true of recognising income on a performance to date basis? 1. It can be an allowable basis for income recognition under IFRS 15 2. It is always an appropriate fall back method where there is no billing schedule within a contract 3. It is always inappropriate where the billing schedule is conditional on meeting success criteria 4. The appropriateness or otherwise of using it as a basis for income recognition is determined solely by the enforceable right to charge on a performance to date basis under the terms of the contract -0 1&2 01&3 O 1&4 1. 3 & 4