B
To be honest, you have been quite lucky (so far). with your husbands ESA claim, other claimants, in these circumstances, have had their claims closed for not attending the medical and failing to provide Good Cause.
With regard the Carers Allowance, you really need to get face to face advice, as ESA and CA overlap, and it will depend on your circumstances, as to whether you actually receive any additional payments.
You will also need to consider whether you husband caring for you is consistent with his health issues and the ESA descriptors. Claiming CA would be a Change of Circumstances and would require hin/you to notify the DWP.
Where to get advice? Gordon