The answer is #5. Squamous-cell carcinoma (above is another image that shows squamous cell and basal cell. A biopsy is needed to confirm diagnosis).
The squamous cell lesion is exophytic and hyperkeratotic with central ulceration, features that are most typical of a squamous-cell carcinoma. Basal-cell carcinomas typically present as a papule with a pearly border. Granuloma fissuratum refers to a mass of granulation tissue. Melanomas are often flat and hyperpigmented. Seborrheic keratosis typically originates on the back of the ear.
Remember, any new skin change should be shown to your physician.