A patient complains of the discolouration of an unrestored upper central incisor. Radiographically, the pulp chamber and the root canal space are obliterated, there is no evidence of caries and the periodontal ligament space appears normal. An external bleaching procedure has not been successful. The most appropriate treatment would be to

perform root canal treatment and fabricate a post retained porcelain fused to metal crown.

fabricate a porcelain veneer.

perform root canal treatment and nonvital bleaching

fabricate a porcelain fused to metal crown

perform root canal treatment and fabricate a porcelain veneer