Explanation:

'Dense' means completely covered or opaque, which is incontextual.

'Commendatory' means favourable, which is also absurd here because the word 'even' indicates a contradictory situation here.

'Inept' means unskillful, which is irrelevant to the context.

'Difficult' clearly suits the context as it justifies the contradicton of Tata motor's good performance inspite of bad time for the industry.

Hence option D is correct.