Can you equalize against Peter Leko?

I had been walking for what felt like days along a dark forest path. A heavy fog covered the trees, and it was cold and quiet, so quiet that the only sounds I had heard for hours were my own footsteps.

Then, up ahead, I noticed a faint light underneath the cloudy haze. As I stepped closer, I saw what appeared to be a chess table, lit by candles in the darkness. I looked further, and I was surprised to see a man sitting there, completely calm, with his hands folded.

Peter Leko looked up.

“I can show you the way out of here,” he said. For a moment, I felt hope to finally return home.

“But hang on! -- first you must answer my riddle.”
He gestured toward the chessboard, and played 1.e4 e5 2.Nf3. "Tell me," Leko asked, "which path do you choose to equalize against me?"

a) The Berlin
b) The Petroff
c) The Marshall
d) A sideline of the Ruy Lopez

a) The Berlin

Leko's main weapon as Black is the Berlin and he is an expert in the Berlin endgame with both sides. Playing the Berlin seems to be a safe choice, but it unfortunately walks right into his preparation and fails to equalize.

b) The Petroff

Well, if the Berlin is out of the question, the Petroff seems to be the most logical choice. However, he worked as a second for Ian Nepomniachtchi to prepare the Petroff for the 2021 World Championship Match and the following Candidates tournaments (2022 and 2024), where Nepo was undefeated in the Petroff. Unfortunately, the Petroff again walks right into his preparation and fails to equalize.

"My favourite victory is when it is not even clear where my opponent made a mistake" - Peter Leko

c) The Marshall

Remember that Leko works with Vincent Keymer, who has played the Marshall as his main choice against the Ruy Lopez for years. Because of this, unfortunately, the Marshall again walks right into his preparation and fails to equalize.

d) A sideline of the Ruy Lopez

This appears to be the smartest choice, hoping to surprise Leko with something he is unprepared for. But Leko is ready for this, because he has already expected the unexpected. Unless you are a top-10 player like Arjun Erigaisi, this approach again walks into his preparation and fails to equalize.

What do you think is the answer to Leko's riddle?