I believe that there is a subtle difference between "as" and "is" here. If she bent her head as a sign of gratitude, she did so to show someone else her gratitude. If she bent her head in a sign of gratitude, she did so because she felt the need to show gratitude.Which one is correct AS or IN?
Context:
She bent her head as/ in a sign of gratitude.
I believe that there is a subtle difference between "as" and "is" here. If she bent her head as a sign of gratitude, she did so to show someone else her gratitude. If she bent her head in a sign of gratitude, she did so because she felt the need to show gratitude.