Name the total number of frequency Mhz with class of d and call sign of k201bm and ERP W less than 74
CREATE TABLE "external_links" (
  "call_sign" text,
  "frequency_m_hz" real,
  "city_of_license" text,
  "erp_w" real,
  "class" text,
  "fcc_info" text
);
SELECT COUNT("frequency_m_hz") FROM "external_links" WHERE "class"='d' AND "call_sign"='k201bm' AND "erp_w"<74;