Final answer:
The provided excerpts do not contain direct evidence of the stranger's intent to hide his identity from Chapter 3 of 'The Scarlet Letter,' but a finger on lips gesture is a common sign of seeking secrecy.
Step-by-step explanation:
The best evidence that the stranger in the marketplace wants to keep his true identity a secret in Chapter 3 of The Scarlet Letter is not provided in the given excerpts. However, if one considers the broader context of the novel, an action such as a finger on lips gesture would typically symbolize a desire for secrecy. This would be a strong indication of the stranger's intention to hide his identity, consistent with behaviors suggesting caution or concealment. The other options like 'white man in strange disarray', 'writhing horror twisted across features', 'remarkable intelligence in features', and the various other excerpts provided do not directly convey a clear desire to keep one's identity secret.