Final answer:
Option d, a survey suggesting that negotiation success is unrelated to physical attributes, casts doubt on the relationship between height and resolve in negotiations as it implies other factors are more significant.
Step-by-step explanation:
The question pertains to the factor that potentially casts doubt upon the relationship between height and resolve in negotiations. Among the options provided, the one that potentially casts doubt is: d. A survey suggesting that negotiation success is unrelated to physical attributes. This statement directly challenges the notion that height could impact a person's ability in negotiations, implying that other factors are more significant.
Anecdotal evidence (option b) is not a strong basis for scientific conclusions, as it does not constitute systematic research and is subject to bias. A positive correlation (option a) would support, rather than cast doubt on, the relationship between height and negotiation success. Similarly, a genetic link (option c) would suggest an inherent correlation rather than casting doubt. However, negotiation success being unrelated to physical attributes (option d) provides a counterpoint to any argument supporting a relationship between height and negotiation outcomes, making it the correct choice for casting doubt on such a relationship.