For most of us section (c) is quite important, which increases the 90 days to 120 days if the three landings are done under supervision of a TRI or TRE.
(c) Specific requirements for commercial air transport:
(1) In the case of commercial air transport, the 90-day period prescribed in subparagraphs (b)(1) and (2) above may be extended up to a maximum of 120 days, as long as the pilot undertakes line flying under the supervision of a type rating instructor or examiner.