Brunswick, Georgia, USA

A few ornamental, fruit-bearing trees frame the yacht harbor in Brunswick. What kind of fruit is it? (a) Finger lime, (b) Persian lime, (c) Key lime, (d) Kaffir lime, (e) Bergamot lime, (f) Desert lime,  (g) Round lime. Bet you didn't know there were so many types of limes? Or might this be a lemon? [2018]