The correct answer is D) parallel. In a parallel configuration, the positive terminals of the batteries are connected together, and the negative terminals are also connected together. This allows each battery to operate independently, with the total current being the sum of the individual battery currents. This is the typical configuration for multiple wet cell storage batteries used to power electrical systems on vessels, as it provides redundancy and allows individual batteries to be charged or replaced without affecting the overall system. The other options are incorrect because: A) series configuration connects the batteries end-to-end, which is not typical for this application; B) compound configuration combines series and parallel connections, which is not the case here; and C) tandem configuration refers to batteries placed one behind the other, which is also not the case in the given illustration.