Thea does not want lovborg to know that she was worried about him because

she wants to keep her love a secret

it suggests a lack of faith in him

it might drive him to hedda

they had just had a fight over trust issues

Thea kept her worries secret because she want to keep her love for Lovborg a secret. The correct option is A. Thea hinted to Hedda in their conversation that she no longer care about her husband but instead have feelings for Lovborg and she is worried over his habit of drunkenness. 

The questions answer is Meteoroid. Hope this helps. Good luck