Pointing to a photograph, a Nancy tells Millan, "I am the only daughter of this lady and her son is your maternal uncle. How is the Nancy related to Millan’s father?

Wife

↑ or ↓ ⇒ Upward or downward line shown "generation gap".

   =    ⇒ Double lines shown "relation b/w Husband & Wife"

   —   ⇒ single line shown "relation in same generation other than Husband & Wife".

   +   ⇒ Plus sign shown " Male".

   -   ⇒ Plus sign shown " Female".

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ATQ,

The 2nd option is satisfying the equation.

Therefore, 2nd option is correct.