What is the name of the Doctor's companion from the 1970s who was a journalist?

What is the name of the Doctor's companion from the 1970s who was a journalist? The answer is Sarah Jane Smith. Played by Elisabeth Sladen, Sarah Jane first appeared in The Time Warrior in 1973 and travelled with the Third and Fourth Doctors.

Sarah Jane was introduced as an investigative journalist pursuing a story about a top-secret research facility. Her curiosity, independence and willingness to challenge authority made journalism an important part of her character rather than a minor biographical detail. She remained with the programme through 1976, appearing in stories with Jon Pertwee and Tom Baker.

The other options belong to different companion eras. Jo Grant travelled with the Third Doctor before Sarah Jane, while Leela joined the Fourth Doctor after Sarah Jane's departure. Romana was also a Fourth Doctor companion, but she was a fellow Time Lord rather than a journalist.

Sarah Jane later became one of Doctor Who's most prominent legacy characters. She returned in the 2006 episode School Reunion and led the spin-off The Sarah Jane Adventures from 2007 to 2011, where she continued investigating alien activity on Earth.