Three of the following are evidence that charophytes are the closest algal relatives of plants. select the exception.
a. similar sperm structure
b. the presence of chloroplasts
c. similarities in cell wall formation during cell division
d. genetic similarities in chloroplasts

b. the presence of chloroplasts

Explanation:

The presence of chloroplast is a character being common to all the groups of green algae (to which charophytes belong) but also to plants, if one associates "plants" to the group formed by non vascular plants (mosses and relatives), non seeded vascular plants (ferns and lycophytes) and seeded plants (conifers or gymnosperms and flowering plants or angiosperms).

Thus, as the presence of chloroplasts is common throughout all these groups, it does not provide any taxonomic relevant information to particular link the charophytes to the land plants (or embryophytes, all the taxa above mentioned) as their closest relatives.  

currents is the correct answer.