Error on line 93 of Question.php

After installing and using WPQST for several surveys on my website (flat5.net) in 2012, a few years went by. Trying to display those old web pages now, however, I get an error display:

Parse error: syntax error, unexpected T_PAAMAYIM_NEKUDOTAYIM, expecting ‘]’ in /home/content/04/8244204/html/wordpress/wp-content/plugins/wp-survey-and-quiz-tool/lib/Wpsqt/Question.php on line 93

This happens at https://flat5.net/2012/10/monday-quiz-2/

WordPress is version 4.3.1 and WPQST is version 2.14

Can you help? ([email protected])

https://www.ads-software.com/plugins/wp-survey-and-quiz-tool/