Need new laptop, want it to play Diablo III. Advice, please?

My laptop is on its last legs. I want my new laptop to be able to play Diablo III reasonably well, but it's been years since I've bought a new computer, and price is a big consideration. I've narrowed the choices down to three, each with dedicated graphics--any recommendations on which would be best (or telling me if none of them would be any good for D3, or that they're all equally unimpressive) would be greatly appreciated.

Their specs, in order of increasing price:

Option 1:
CPU: AMD A6-3420M 1.5GHz (quad-core)
GPU: AMD Radeon HD 6650M
Memory: 6GB. Max 8GB
Screen size: 15.6". Max resolution: 1366x768

Option 2:
CPU: CPU: AMD A6-3420M 1.5GHz (quad-core)
GPU: AMD Radeon HD 7670M
Memory: 4GB (2x2). Max 8GB
Screen size: 15.6". Max resolution: 1366x768

Option 3:
CPU: Intel Core i5-2450M 2.5GHz (dual-core)
GPU: AMD Radeon HD 7670M
Memory: 4GB (1x4). Max 8GB
Screen size: 17.3". Max resolution: 1600x900

*Edit: I'm willing to upgrade the RAM, but of course would rather not have to because it adds to the price.
Second edit: I'm an idiot.