According to Economic Survey 2017 - 18, the Indian economy is becoming more formalized. This is indicated by which of the following shifts? Select the correct answer from the codes given below :

(a) The introduction of GST has brought more firms into the indirect tax net.

(b) After demonetization, a significant increase has taken place in the number of individuals filing income tax returns.

(c) An increase in savings in the formal financial sector.

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