[Grade 11 Physics: Kinematics] I cant figure out why my velocity direction is wrong in this problem

I'm working on a problem about a car braking to a stop. The initial velocity is 25 m/s east and it comes to a stop in 8 seconds. I calculated acceleration as -3.125 m/s^2 because it's slowing down. But when I use that to find velocity at t=4 seconds I get 12.5 m/s east which seems right. However the answer key says my acceleration should be positive and my direction is wrong. Im confused because deceleration is negative acceleration right

Ive checked the problem statement multiple times and it definitely says the car is moving east and braking. My instructor mentioned something about picking a sign convention consistently but I thought I did that by making east positive. If acceleration is negative and velocity becomes zero at t=8 then at t=4 velocity should still be east and positive. Why would the answer key say acceleration is positive

Can someone explain where my sign convention is breaking down I feel like Im missing something fundamental about how to assign directions for velocity and acceleration in kinematics problems.