Blue litmus paper is dipped in …

Blue litmus paper is dipped in a solution. It remains blue. The nature of solution is

<input id="option_0_7_0" name="opt_0_7" ng-checked="vm.quiz.getOptionSelectedStatus(vm.quiz.currentSection, vm.quiz.currentQuestion, $index)" ng-click="vm.quiz.setOptionSelectedStatus(vm.quiz.currentSection, vm.quiz.currentQuestion, $index, '1')" type="radio" /><label for="option_0_7_0" ng-bind-html="option.option">Either basic or acidic</label>

<input id="option_0_7_1" name="opt_0_7" ng-checked="vm.quiz.getOptionSelectedStatus(vm.quiz.currentSection, vm.quiz.currentQuestion, $index)" ng-click="vm.quiz.setOptionSelectedStatus(vm.quiz.currentSection, vm.quiz.currentQuestion, $index, '1')" type="radio" /><label for="option_0_7_1" ng-bind-html="option.option">Neither basic nor neutral</label>

<input id="option_0_7_2" name="opt_0_7" ng-checked="vm.quiz.getOptionSelectedStatus(vm.quiz.currentSection, vm.quiz.currentQuestion, $index)" ng-click="vm.quiz.setOptionSelectedStatus(vm.quiz.currentSection, vm.quiz.currentQuestion, $index, '1')" type="radio" /><label for="option_0_7_2" ng-bind-html="option.option">Neither acidic nor basic</label>

<input id="option_0_7_3" name="opt_0_7" ng-checked="vm.quiz.getOptionSelectedStatus(vm.quiz.currentSection, vm.quiz.currentQuestion, $index)" ng-click="vm.quiz.setOptionSelectedStatus(vm.quiz.currentSection, vm.quiz.currentQuestion, $index, '1')" type="radio" /><label for="option_0_7_3" ng-bind-html="option.option">Either basic or neutral</label>

<a href="javascript:void(0);" ng-click="vm.quiz.resetSelectedOptions(vm.quiz.currentSection, vm.quiz.currentQuestion)">Clear</a>