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Find one correct method to check divisibility by $11$. Select ONE answer.

Write $n$ in decimal digits. If the last digit is $1$, then $11$ divides $n$.

Write $n$ in decimal digits. If the last two digits are $11$, then $11$ divides $n$.

Write $n$ in decimal digits. If the alternating sum of the digits is divisible by $11$, then $11$ divides $n$.

Write $n$ in decimal digits. If the sum of the digits is divisible by $11$, then $11$ divides $n$.