Explanation
The project manager should discuss with the client alternative approaches to deliver the minimal viable product (MVP) in 4 months and the rest later. The MVP is a version of the product that has enough features to satisfy the customer's needs and provide feedback for future development1. This approach can help to meet the client's urgency and budget, while also allowing the project manager to manage the scope and quality of the product. Calling a meeting with the client to explain that 4 months is not enough time (A) may not be effective or satisfactory, as the client may not accept the project manager's estimation or rationale. Motivating the team to work more efficiently and approve overtime (B) may not be feasible or desirable, as it may lead to burnout, stress, and reduced quality of the product. Seeking additional resources from subcontractors and other sources (D) may not be possible or beneficial, as it may introduce new risks, costs, and coordination issues to the project. References: 1: Minimum Viable Product (MVP) - Definition and Examples | Aha!